141 citations · 997 across the 25 of their papers we have counts for
25 papers
Oscillation-Free Unconventional Photon Blockade from Quadrature Driving of a Kerr Dimer
Hamid Ohadi
We demonstrate unconventional photon blockade in a symmetric Kerr dimer driven with equal-amplitude fields at a phase difference. The minimum inter-cavity coupling is $J…
Ultra-small Mode Volume Polariton Condensation via Precision Ion Implantation
Y. C. Balas, X. Zhou, E. Cherotchenko +7
We present a novel method for generating potential landscapes in GaAs microcavities through focused implantation. The ion beam imprints micron-scale patterns of non-radiat…
Nonlinear Rydberg exciton-polaritons in CuO microcavities
Maxim Makhonin, Anthonin Delphan, Kok Wee Song +13
Rydberg excitons (analogues of Rydberg atoms in condensed matter systems) are highly excited bound electron-hole states with large Bohr radii. The interaction between them as well…
Laser Writing of Parabolic Micromirrors with a High Numerical Aperture for Optical Trapping and Rotation
T. Plaskocinski, Y. Arita, G. D. Bruce +4
On-chip optical trapping systems allow for high scalability and lower the barrier to access. Systems capable of trapping multiple particles typically come with high cost and comple…
Ultralong temporal coherence in optically trapped exciton-polariton condensates
K. Orfanakis, A. F. Tzortzakakis, D. Petrosyan +2
We investigate an optically trapped exciton-polariton condensate and observe temporal coherence beyond 1~ns duration. Due to the reduction of the spatial overlap with the thermal r…
Quantum confined Rydberg excitons in CuO nanoparticles
Konstantinos Orfanakis, Sai Kiran Rajendran, Hamid Ohadi +4
The quantum confinement of Rydberg excitons is an important step towards exploiting their large nonlinearities for quantum applications. We observe Rydberg excitons in natural nano…
Synchronization crossover of polariton condensates in weakly disordered lattices
H. Ohadi, Y. del Valle-Inclan Redondo, A. J. Ramsay +5
We demonstrate that the synchronization of a lattice of solid-state condensates when inter-site tunnelling is switched on, depends strongly on the weak local disorder. This finding…
Strain-assisted optomechanical coupling of polariton condensate spin to a micromechanical resonator
O. Be'er, H. Ohadi, Y. del Valle-Inclan Redondo +5
We report spin and intensity coupling of an exciton-polariton condensate to the mechanical vibrations of a circular membrane microcavity. We optically drive the microcavity resonat…
Spin order and phase transitions in chains of polariton condensates
H. Ohadi, A. J. Ramsay, H. Sigurdsson +8
We demonstrate that multiply-coupled spinor polariton condensates can be optically tuned through a sequence of spin-ordered phases by changing the coupling strength between nearest…
A driven-dissipative spin chain model based on exciton-polariton condensates
H. Sigurdsson, A. J. Ramsay, H. Ohadi +4
An infinite chain of driven-dissipative condensate spins with uniform nearest-neighbor coherent coupling is solved analytically and investigated numerically. Above a critical occup…
Tunable magnetic alignment between trapped exciton-polariton condensates
H. Ohadi, Y. del Valle-Inclan Redondo, A. Dreismann +6
Tunable spin correlations are found to arise between two neighboring trapped exciton-polariton condensates which spin-polarize spontaneously. We observe a crossover from an antifer…
Polariton Spin Whirls
Pasquale Cilibrizzi, Helgi Sigurdsson, Tim C. H. Liew +5
We report on the observation of spin whirls in a radially expanding polariton condensate formed under non-resonant optical excitation. Real space imaging of polarization- and time-…
Half-Skyrmion Spin Textures In Polariton Microcavities
Pasquale Cilibrizzi, Helgi Sigurdsson, Tim C. H. Liew +8
We study the polarization dynamics of a spatially expanding polariton condensate under nonresonant linearly polarized optical excitation. The spatially and temporally resolved pola…
Fractional quantum mechanics in polariton condensates with velocity dependent mass
Florian Pinsker, Weizhu Bao, Yong Zhang +3
We introduce and analyze a novel mean-field model for polariton condensates with velocity dependence of the effective polariton mass due the photon and exciton components. The effe…
Spontaneous spin bifurcations and ferromagnetic phase transitions in a spinor exciton-polariton condensate
H. Ohadi, A. Dreismann, Y. G. Rubo +6
We observe a spontaneous parity breaking bifurcation to a ferromagnetic state in a spatially trapped exciton-polariton condensate. At a critical bifurcation density under nonresona…
Robust platform for engineering pure-quantum-state transitions in polariton condensates
A. Askitopoulos, T. C. H. Liew, H. Ohadi +3
We report on pure-quantum-state polariton condensates in optical annular traps. The study of the underlying mechanism reveals that the polariton wavefunction always coalesces in a…
Dissipative phase locking of exciton-polariton condensates
H. Ohadi, R. L. Gregory, T. Freegarde +3
We demonstrate, both experimentally and theoretically, a new phenomenon: the presence of dissipative coupling in the system of driven bosons. This is evidenced for a particular cas…
Linear wave dynamics explains observations attributed to dark-solitons in a polariton quantum fluid
P. Cilibrizzi, H. Ohadi, T. Ostatnicky +3
We investigate the propagation and scattering of polaritons in a planar GaAs microcavity in the linear regime under resonant excitation. The propagation of the coherent polariton w…
The Non-linear Optical Spin Hall Effect and Long-Range Spin Transport in Polariton Lasers
Elena Kammann, Timothy C. H. Liew, Hamid Ohadi +6
We report on the experimental observation of the non-linear analogue of the optical spin Hall effect under highly non-resonant circularly polarized excitation of an exciton polarit…
Spontaneous symmetry breaking in a polariton and photon laser
Hamid Ohadi, Elena Kammann, Timothy C. H. Liew +3
We report on the simultaneous observation of spontaneous symmetry breaking and long-range spatial coherence both in the strong and the weak-coupling regime in a semiconductor micro…
Crossover from exciton-polariton to photon Bose-Einstein condensation
Elena Kammann, Hamid Ohadi, Maria Maragkou +2
BEC of exciton-polaritons and related effects such as superfluidity1,2, spontaneous symmetry breaking3,4 and quantised vortices5,6 open way to creation of novel light sources7 and…
Magneto-optical trapping and background-free imaging for atoms near nanostructured surfaces
Hamid Ohadi, Matthew Himsworth, André Xuereb +1
We demonstrate a combined magneto-optical trap and imaging system that is suitable for the investigation of cold atoms near surfaces. In particular, we are able to trap atoms close…
Hänsch--Couillaud locking of Mach--Zehnder interferometer for carrier removal from a phase-modulated optical spectrum
J. E. Bateman, R. L. D. Murray, M. Himsworth +3
We describe and analyse the operation and stabilization of a Mach--Zehnder interferometer, which separates the carrier and the first-order sidebands of a phase-modulated laser fiel…
Dynamics of axialized laser-cooled ions in a Penning trap
E. S. Phillips, R. J. Hendricks, A. M. Abdulla +5
We report the experimental characterization of axialization - a method of reducing the magnetron motion of a small number of ions stored in a Penning trap. This is an important ste…